Tension device



W. C. MEYER TENSION DEVICE Filed April 13 1920 2 Sheets-Sheet 1 Apr. 17, 1923.

W. C. MEYER TENSION DEVICE Filed April 13, 1920 2 Sheets-Sheet 2 Patented Apr. 1?, 1923.

UNETED STATES hATlENT @FFHQE.

WILLIAM C. MEYER, OF BEVERLY, M'ASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW J EBSEY.

TENSION DEVICE.

Application filed April 13, 1920.

T 0 all whom it may concern Be it known that I, WILLIAM C. MEYER, a citizen of the United States, residing at Beverly, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Tension Devices; and I do hereby declare the followfreely from the supply in removing a shoe from the machine. Such machines have also been provided with a thread severing knife for severing the thread between the shoe and the machine, and with a thread gripping device for holding the free end of the thread projecting from the thread handling devices after the thread is severed, the thread being drawn between the jaws of the gripping device across the edee of the knife by the operator in removing a shoe from the machine. The thread grinning device holds the thread during at least the first cycle of operations upon starting the machine to insure the proper formation of the first stitch. It is desirable in such machines that the tension be held in released condition until after the take-up completes its first loop-drawing stroke upon starting the machine to prevent the thread from being drawn from between the jaws of the gripping device at this time by the action of the take-up.

The primary object of the present invention is to provide sewing machines with novel and improved mechanism for holding the tension in released condition during the first part of a seam formation.

With the above object in view the invention comprises various novel and improved. constructions, arrangements and combinations of parts hereinafter described and particularly pointed in the claims the advantages of which will be readily understood and appreciated by those skilled in the art.

ciated parts.

Serial No. 373,502.

The invention will be clearly understood from the accompanying drawings illustratmg a machine embodying the invention in its preferred form and the followin detailed description of the constructions therein shown.

in the drawings Figure 1 is a view in side elevation of an inseam shoe sewing machine embodying the invention; Fig. 2 is a view in side elevation of a portion of the machine illustrating particularly the tension mechanism; Fig. 3 is a detail sectional view taken substantially on the line 33 of Fig. 2; and Fig. 4 is a plan view partly in section of the mechanism shown in Fig. 3 and certain asso- The machine illustrated in the drawings is especially constructed for sewing inseams of welted shoes and, except as hereinafter described, has the same construction, arrangement and mode of operation of parts as the machine illustrated and described in applicants application, Serial No. 95,893. filed May (3, 1916, renewed June 17, 1920, Serial No. 389,774, on which Patent No. 1,411,798, issued, April 4, 1922. The machine comprises a curved hook needle (not shown), a looper 2, a thread finger 4, a take-up 6, and a tension wheel 8, all cooperating to form a chainstitch seam. The machine is also pro vided with a thread cutting knife 9 for severing the thread between a shoe and the machine after the completion of a seam and with a thread gripping device 10 for holding the free end of the thread projecting from the thread handling devices after the thread is severed, the thread being inserted between the jaws of the gripping device and drawn across the edge of the knife by the. operator in removing a shoe from the machine.

The take-up 6 consists of a thread truck mounted on one arm of a lever 11 pivoted at 12 on the frame, the rear end of which has a shoes 28 and 30 having linings of felt indicated at 32 contacting with the peripheral surface of the brake drum. The lower brake shoe 30 is pivotally supported by an arm 34 pivoted at 36 on the frame. The brake shoes are pivotally connected by means of a pin 38 and are held in proper relation to the brake drum by means of a spring 40. The brake shoes are forced into engagement with the periphery of the brake drum by the downward pressure of a lever 42 pivoted at 44 and connected with the upper brake shoe 28. The lever 42 is connected with the upper brake shoe by means of a rod 46 pivoted to said brake shoe and a roll clutch 50 carried by said lever and arranged to clutch the rod. The lever 42 is engaged by an abutment carried by a slide mounted toslide longitudinally in a lever 54 pivoted on a stud 56, the slide being arranged to be adjusted int-he lever 54 to adjust the tension by means of a hand lever 58 pivoted at 60 on the lever 54 and connected with the slide. The lever 54 is pressed upon yieldingly by a pin 62 mounted to a slide in a sleeve 64 carried at the forward end of a lever 66, the pin being acted upon by a coiled spring 68. The lever 66 is pivoted at 69 on the frame and the rear end thereof is acted upon by a governor mechanism (not shown) which acts through the lever to vary the pressure of the pin 62 on the lever 54 as the speed of the machine varies.

It is usual in machines of the class illustrated in the present application, after stopping the forward rotation of the main shaft at the completion of a seam, to impart a reverse rotation to the shaft so as to free the last loop of thread from they needle.

The shaft is then finally brought to rest ill with the needle in retracted position so that the shoe may be readily removed from the machine.

To relieve the thread of tension after the completion of a seam, the machine illustrated is provided with a tension release mechanism which, when the direction of rotation of the main shaft is reversed, releases the brake shoes 28 and 30 from braking engagement with the brake drum 26. The tension release mechanism comprises a swinging arm 70 such as is ordinarily employed in tension release mechanism adapted to be operated by a reversal in the direc tion of rotation of the main shaft. This arm is pivotally connected at 7 2 to the downwardly extending arm of a lever 74 mounted on the shaft 18. This lever is provided with a short forwardly extending arm having a socket in which engages the lower end of a rod 76 which has its upper end engaged in a socketin the rear end of the lever 42. The lever 74. acted upon by a coiled spring 77 attached to a lever 7.8 connected by a link 79 with an arm on the lever 74 which tends to maintain the lever 74 and the arm 70 in their normal positions.

With the above construction the downwardly extending arm of the lever74 will be swung forwardly by the movement of the arm 70 upon the reversal of the direction of rotation of the main shaft 22, and the lever 42 will be lifted by the engagement of the rod 76 therewith to relieve the pressure of the brake shoes on the brake drum. The parts of the machine above briefly described have the same construction, arrangement and mode of operation as the corresponding parts of the machine shown and described in applicants pending application referred to above and reference may be had to said application for a full and complete description of the same. The direction of rot-ation of the main shaft is preferably reversed and the rotation of the shaft is stopped at a predetermined point in its reverse movement-with the needle in its limiting retracted position by automatically acting mechanism as illustrated and described in said application.

hen the direction of rotation of the main shaft is reversed to free the last loop from the needle and the shaft is stopped with the needle in retracted position. the position of the shaft is such that almostimmediately upon starting the machine the arm 70 will be restored to its normal position and the downwardly extending arm of the lever 7 4 will be swung rearwardly. The parts of the machine are so timed that upon starting the machine, after the arm 70 and the lever 74 have been restored to their normal positions in the manner described, the take-up will execute its first loop-drawing stroke.

To hold the tension in released condition substantially until. the take-up has completed its first loop(ilrawing stroke upon starting the machine, so that the thread will not be drawn from the gripping device 10 by the action of the take-up, a latch 80 is provided to hold the lever 42 in elevated position. The latch 80 is pivoted on the stud 56 and is provided at its lower end with a rearwardly directed projection 81 arranged to engage beneath a lateral. projection 82 on the lever 42. The projection on the lower end of the latch normally occupies a position in front of the lateral pro 'iection on the lever 42. As the lever 42 is lifted upon stopping the machine, the latch is swung rearwardly'to engage the vprojection thereon beneath the lateral projection on the lever 42 by means of a coiled spring 63. The latch will hold the tension released as the arm 70 and lever 74 are restored to their normal positions upon starting the machine.

As thetake-iip completesit s first l opdrawing stroke, the latch is swung forwardly to release the lever 42 by means of an arm Set secured to a rock shaft 86 and arranged to engage an abutment or shoulder on the latch. A second arm 88 is secured to the rock shaft 86 and the arm 84 is actuated to release the latch in timed relation to the movement of the take-up by means of an arm 90 formed on the take-up cam lever 16 and arranged to engage the arm 88.

Having explained the nature and object of the invo ution, and having specifically described a machine embodying the invention ann its preferred form, what is claimed 1s:

1. A sewing machine having, in combination, stitch forming devices, a tension wheel, a brake for retarding the rotation of the tension wheel, a main shaft from which said devices are operated, means for releasing the brake upon the reversal of the direction of rotation of the main shaft, a latch for holding the brake in released condition upon starting the machine, and means for releasing the latch.

2. A sewing machine having, in combination, a needle, take-up mechanism comprising a thread engaging device and means for actuating said device to take up the thread during each cycle of operations, a tension wheel, a brake for retarding the rotation of the tension wheel, means for releasing the brake topermit the thread to be drawn freely from the supply while the machine is at rest, a latch for holding the brake in released condition upon starting the machine, and means actuated from the take-up mechanism for throwing out the latch.

3. A sewing machine having, in combination, stitch forming devices, a tension wheel, a brake for retarding the rotation of the tension wheel comprising a brake wheel, pivotally connected brake shoes for engagement with the periphery of the brake wheel, means for supporting one of said shoes for movement toward and from the brake wheel, a lever connected with the other brake shoe, means acting yieldingly on the lever in one direction to engage the brake shoes with the brake wheel, means for moving the lever in the opposite direction to release the pressure of the brake shoes on the brake wheel upon stopping the machine, a latch for holding the lever in brake released position upon starting the machine, and means for thereafter releasing the latch.

4. A sewing machine having, in combination, stitch forming devices, a tension wheel, a brake for retarding the rotation of the tension wheel comprising a brake wheel, a brake shoe for engaging the brake wheel, a lever connected with the brake shoe, means acting yieldingly on the lever in one direction to engage the brake shoe with the brake wheel comprising a lever, a slide mounted on the lever, an abutment carried by the slide for engaging the first lever, a governor controlled lever, a spring pressed pin carried thereby and arranged to engage the second lever, means for swinging the first lever in a direction to release the pressure of the brake shoe on the brake wheel on stopping the machine, a pivoted latch for holding the first lever in brake released position upon starting the machine, and means for throwing out the latch.

5. A sewing machine having, in combination, stitch forming devices, take-up mechanism, atension wheel, a brake for retarding the rotation of the tension wheel comprising a brake wheel, a brake shoe for engaging the brake wheel, a lever connected with the brake shoe, means acting yieldingly on the lever in one direction to engage the brake shoe with the brake wheel comprising a second lever, a slide mounted on the second lever, an abutment carried by the slide for engaging the first lever, a governor controlled lever, a spring pressed pin carried thereby and arranged to engage the second lever, means for swinging the first lever in a direction to release the pressure of the brake shoe on the brake wheel on stopping the machine, a pivoted latch for holding the first lever in brake released position upon starting the machine, and means actuated from the take-up mechanism for throwing out the latch.

WILLIAM o. MEYER 

